Rutgers professor creates course to research extraterrestrial life

Nathan Yee, a Rutgers University—New Brunswick professor of geomicrobiology and geochemistry, teaches a course that evaluates whether there is life on other planets, according to a University press release. 

Yee has been working on a research team focused on looking into how proteins evolved to become the catalysts of life on Earth, according to the release. Now, he hopes to take what he knows about the evolution of life on Earth and apply it to the evaluation of whether life exists in outer space. 

“When I was a kid, I asked my science teacher if we were alone in the universe. My teacher said there may be no way of knowing, but I think that is changing,” Yee said, according to the release. Scientists have transformed research into whether extraterrestrial life exists in the past few decades, developing new tools to search for life outside of the Earth’s orbit.

“Two of the biggest game-changers are the Curiosity rover, which is analyzing rocks on Mars to seek evidence of past or current life, and the new space telescopes discovering strange new exoplanets that orbit other stars,” Yee said, according to the release. “The next generation of telescopes will study the atmospheres of these planets. We know that most oxygen on Earth is made by photosynthetic bacteria. So, if we find oxygen in exoplanets, that might mean there had been plants and maybe even animals that breathe oxygen. None of this was possible when I was a kid.” 

Yee said that he is helping NASA with its Curiosity mission, aimed to determine whether Mars ever was or could be habitable to microbial life, according to the release. 

“Since 2014, NASA has been inviting me to participate in workshops and panels involving special regions on Mars and the Mars 2020 mission. They wanted someone with expertise about microbes interacting with minerals and the biosignatures that ancient Earth microbes left behind in rocks after they died and went extinct, which happens to be my area of expertise at Rutgers’ Department of Earth and Planetary Sciences,” Yee said, according to the release. 

This work at NASA is what inspired Yee to begin teaching a course at Rutgers, which looks at whether life exists on Mars, and compares the ecological differences between Earth and the red planet, according to the release. 

“Earth is 4.5 billion years old, yet one amazing discovery is that life evolved very quickly on Earth. In the beginning of Earth’s formation, the planet was really hot and liquid water wasn't stable. Any water existed in the form of vapor. As it cooled, it rained and evaporated over and over, eventually leading to the formation of oceans. Once oceans were in place, life quickly emerged in the form of microorganisms,” Yee said, according to the release. 

In contrast, Mars does not have any oceans to support life. Instead, Mars is a cold and dry planet that was once warm and wet, he said, according to the release. The only life that has been found on Mars is located in methane. 

When looking for life outside of Earth, scientists' best bets are still on moons and planets that have water, which is something several places in Earth’s solar system have, Yee said, according to the release.

“Also, everywhere there is liquid water on Earth, we’ve found microbial life. We are smart enough to know that if a world has oceans, then we should look there for alien microbes,” Yee said, according to the release. “Europa, which is one of Jupiter’s moons, has what appears to be global oceans under sheets of ice. Saturn’s moon Enceladus has geysers and hot springs spewing from its south pole. That points to the possibility of volcanoes and hydrothermal vents, which on Earth harbor ancient life forms and may have contributed to the origin of life here.”